Waste from peach (Prunus persica) processing used for optimisation of carotenoids ethanolic extraction

The processing of peaches to produce fruit pulp generates solid and liquid wastes rich in phytochemicals, such as carotenoids; thus, the objective of this work was to study the use of this waste for carotenoid extraction based on a complete experimental design and using response surface methodology. The parameters studied were the amount of solvent (20–50 mL), the number of extractions (1–5) and the extraction time (10–30 min). The extracts were analysed by spectrophotometry and the optimised conditions by HPLC. The optimised results were four extractions of 10 min using 38.5 mL of ethanol, which presented a yield of 168.59 μg g^?1 DW of total carotenoids of which 67.55 μg g^?1 corresponds to β‐carotene, 86.75 μg g^?1 to cryptoxanthin, 12.08 μg g^?1 to zeaxanthin and 2.2 μg g^?1 to lutein, which representing 66% of extraction pigments relative to the total content of carotenoids present in the peach waste.     

Safety improvement and preservation of typical sensory qualities of traditional dry fermented sausages using autochthonous starter cultures

Traditional dry fermented sausages are manufactured without addition of starter cultures in small-scale processing units, their fermentation relying on indigenous microflora. Characterisation and control of these specific bacteria are essential for the sensory quality and the safety of the sausages. The aim of this study was to develop an autochthonous starter culture that improves safety while preserving the typical sensory characteristics of traditional sausages. An autochthonous starter composed of Lactobacillus sakei, Staphylococcus equorum and Staphylococcus succinus isolated from a traditional fermented sausage was developed. These strains were tested for their susceptibility to antibiotics and their production of biogenic amines. This starter was evaluated in situ at the French traditional processing unit where the strains had been isolated. Effects of the autochthonous starter were assessed by analysing the microbial, physico-chemical, biochemical and sensory characteristics of the sausages. Inoculation with the chosen species was confirmed using known species-specific PCR assays for L. sakei and S. equorum and a species-specific PCR assay developed in this study for S. succinus. Strains were monitored by pulse-field gel electrophoresis typing. Addition of autochthonous microbial starter cultures improved safety compared with the traditional natural fermentation of sausages, by inhibiting the pathogen Listeria monocytogenes, decreasing the level of biogenic amines and by limiting fatty acid and cholesterol oxidation. Moreover, autochthonous starter did not affect the typical sensory quality of the traditional sausages. This is the first time to our knowledge that selection, development and validation in situ of autochthonous starter cultures have been carried out, and also the first time that S. equorum together with S. succinus have been used as starter cultures for meat fermentation. Use of autochthonous starter cultures is an effective tool for limiting the formation of unsafe compounds in traditional sausage while preserving their original and specific sensory quality.     

A novel method to determine valnemulin in feedingstuffs for several animal species by liquid chromatography-electrospray tandem mass spectrometry

A new method specific for the determination and unambiguous confirmation of the antibiotic valnemulin in feed for all animal species is described. Simple clean-up based on solvent extraction and liquid partition is carried out prior to determination by liquid chromatography coupled to electrospray tandem mass spectrometry on a hybrid QTRAP 4000 system, in multiple reaction monitoring mode. Valnemulin is licensed in the European Union as a veterinary drug for use in feed for pigs and rabbits, but unavoidable carryover in feed for non-target species should be monitored. The method is rapid and reliable, and was validated in-house at 10, 100 and 750 ng g^–1, evaluating the analytical performances according to Commission Regulation (EC) No. 882/2004. Good mean recoveries from 79.7% to 92.6%, and within-laboratory reproducibility RSDs, ranging from 6.2% to 12.1%, were measured; the limit of quantification at 10.0 ng g^–1 also allows for sensitive evaluation of undesirable carryover in feed for non-target species. The results of monitoring 24 compound feeds for several animal species are also reported.     

Chemical vapor generation of arsane in the presence of L-cysteine. Mechanistic studies and their analytical feedback

The complex reactivity of the system As-AH-RSH-THB (As=As(III), As(V); AH=HCl, HClO4, CH3COOH; RSH=L-cysteine (Cys); THB=NaBH4) was investigated using continuous flow (CF) hydride generation (HG) coupled either with atomic absorption (AAS) or atomic fluorescence spectrometry (AFS). AsH3 generation was examined in the presence of Cys by varying acidity and the type of acid, the mixing sequence, and the reaction time of reagents. The strong depression of arsane generation, which is typically observed in the range of acidity of 0.2-2 M HCl, can be addressed to the low reaction rate of thiol-borane, hydroboron complexes, or both toward those As(III) substrates that are formed in the same reaction environment. The simultaneous presence of Cys-borane and As(III)-Cys species is at the origin of the gap of the arsane generation efficiency in the 0.2-2 M HCl acidity range. The selective formation of Cys-borane complexes, which are formed faster than As(III)-thiol complexes, can be achieved by a careful choice of the mixing sequence of the reagents. The simultaneous mixing of sample, Cys, and THB is able to reduce substantially the gap of the arsane generation efficiency in the 0.2-2 M HCl acidity range. These properties were employed to implement a simple method for selective determination of As(III) in samples containing inorganic arsenic: (i) Total inorganic arsenic is determined by sample treatment with 0.2 M Cys for 30 min, acidity 0.1 M HCl, followed by CF-HG-AFS; (ii) As(III) is selectively determined in 0.005 M CH3COOH in the presence of Cys using a chemifold setup allowing the simultaneous mixing of sample, 0.2 M Cys and 0.1 M THB. The selectivity, measured from the ratio between the slopes of calibration graphs As(III)/As(V), is 220. The interference effects of Cu(II), Fe(III), Ni(II), Co(II), Ag(I), Pd(II), and Pt(IV) can be kept under control using the simultaneous mixing of all the reagents. The tolerance toward the interferences was almost the same as that obtained by allowing the formation of As(III)-Cys complexes (offline sample pretreatment with Cys for 30 min). The method was tested with the application to the natural waters and mineral well waters analysis employing CF-HG-AFS.     

Fixed term contracts and employers' human capital: The role of educational spillovers

This paper analyses the role of the employers' education on the spread of temporary contracts. Taking advantage of a unique firm‐level dataset, we test whether the share of fixed term workforce in a firm is affected by the employer's level of education. Furthermore, we test whether knowledge spillovers arising from the agglomeration of university graduate employers affect the incidence of temporary employment in the firms located in the area. In both cases we find a negative effect. Interestingly, only small firms are influenced by the spillovers. The possible problems of endogeneity of the agglomeration variable are coped with an IV approach.     

Mitochondrial Malfunctioning,Proteasome Arrest and Apoptosis in Cancer Cells by Focused Intracellular Generation of Oxygen Radicals

Photofrin/photodynamic therapy (PDT) at sub-lethal doses induced a transient stall in proteasome activity in surviving A549 (p53^+/+) and H1299 (p53^−/−) cells as indicated by the time-dependent decline/recovery of chymotrypsin-like activity. Indeed, within 3 h of incubation, Photofrin invaded the cytoplasm and localized preferentially within the mitochondria. Its light activation determined a decrease in mitochondrial membrane potential and a reversible arrest in proteasomal activity. A similar result is obtained by treating cells with Antimycin and Rotenone, indicating, as a common denominator of this effect, the ATP decrease. Both inhibitors, however, were more toxic to cells as the recovery of proteasomal activity was incomplete. We evaluated whether combining PDT (which is a treatment for killing tumor cells, per se, and inducing proteasome arrest in the surviving ones) with Bortezomib doses capable of sustaining the stall would protract the arrest with sufficient time to induce apoptosis in remaining cells. The evaluation of the mitochondrial membrane depolarization, residual proteasome and mitochondrial enzymatic activities, colony-forming capabilities, and changes in protein expression profiles in A549 and H1299 cells under a combined therapeutic regimen gave results consistent with our hypothesis.     

Use of neural networks for quick and accurate auto-tuning of PID controller

With reference to a real industrial application of process control, some considerations are discussed concerning the accuracy of methods for auto-tuning of proportional, integral and derivative factor (PID). In particular, a theoretical–experimental approach is described, that allows to evaluate the adequateness of new methods for auto-tuning of PID, able to significantly reduce the time duration for auto-tuning with respect to traditional ones. This result has been achieved by using suitable techniques of experimental data processing, based on neural-networks algorithms, set for this specific application. The effect on described methodology of environmental and operating disturbances is also described.